Algae generally includes a large and diverse group of simple, typically autotrophic organisms that grow using photosynthesis. Photosynthesis is a process where plants generate higher-order organic compounds, such as sugars, using a chemical process involving chlorophyll. Chlorophyll is generally characterized by a green pigment found in most living plants.
Because some species of algae grow at a relatively fast rate, their use has been explored in the cultivation of food and energy. Algae of this type has been cultivated in open ponds and in closed reactors in which the algae is suspended in a water solution and periodically provided with nutrients for its growth. Algae cultivation may be performed for various purposes, including industrial and municipal waste water remediation, growing high value food supplements (such as spirulina), growing food for aquaculture, and biofuel cultivation from algal lipids.